This invention relates to a product supply system to be arranged between a product discharge section and an accumulation packaging machine, wherein a plurality of products intermittently discharged from the product discharge section are packaged in a lump.
As shown in FIGS. 6A and 6B, a conventional product supply system for an accumulation packaging machine is of an intermittent push type where a product a is intermittently discharged from a product discharge section M1 connected to a continuously operative packaging machine in a previous stage for example, and is then pushed by a pusher P1 every discharge action to a push conveyance line R1 leading to an accumulation packaging machine M2 in a subsequent stage. There is provided at a final end of the push conveyance line R1 a sensor S for detecting a leading end of a row A of the product as supplied in an intermittent push manner. Upon detection of the leading product a by the sensor S, a product separating device (elevation and swiveling plate) P2 for separating a desired row A1 of the product in the row A of the product is elevated according to a detection signal from a waiting position under the push conveyance line R1 between both conveyor plates or to raise the product row A1 consisting of m-steps and n-rows, or two-steps and five-rows in this case. At an upper limit of elevation, a pusher P3 is projected to feed the product row A1 to a conveyance line R2 leading to the accumulation packaging machine M2, and is then retracted. At the same time, the elevation and swiveling plate P2 is horizontally swiveled at an angle of 90 degrees, and is then lowered. At a lower limit of the plate P2, the plate P2 is horizontally swiveled at an angle of 90 degrees in the reverse direction to be returned to an original position under the push conveyance line R1. On the other hand, the product row A1 of two-steps and five-rows on the conveyance line R2 is accumulated and packaged.
In such a constitution as above, assuming that a time t1 is a period from a time when the sensor S detects the leading product a and the product separating device (elevation and swiveling plate) P2 starts elevating to a time when a lower surface of the product separating device (elevation and swiveling plate) P2 is raised to a height where the product a is not interfered, and that a time t2 is a period from a time when the pusher P1 completely pushes out the product a or the product row A to a time when the pusher P1 starts pushing the next product row A (pusher return time t2), it is required to set the times t1 and t2 in the relation of t1&lt;t2.
In the event that the relation is not satisfied, during elevation of the product row A1 containing (m.times.n) products by means of the elevation and swiveling plate P2, the product in (n+1) row will collide with a tip end of the elevation and swiveling plate P2, thereby hindering smooth operation. Assuming that a time required for feeding one product is t3, a period of motion of the product a, that is, a supply cycle of the product discharge section M1 is t2+t3.
In the prior art system as mentioned above, the product separating device (elevation and swiveling plate) P2 is operated through a cam mechanism in such a manner as to engage and dissengage a clutch and brake mechanism under continuous running condition of a motor in the accumulation packaging machine in the subsequent step.
Accordingly, operation of the product separating device (elevation and swiveling plate) P2 is restricted by the mechanism of such kinds of drive members (motor, clutch and brake), and a high speed operation is limited. Further, when the product discharge section is operated at a high speed, the above-mentioned relation of t1&lt;t2 cannot be maintained.
Furthermore, it is disadvantageous that a detecting timing of the sensor S tends to be inaccurate because of variation in size of the product (e.g., cigarette package) as supplied from the product discharge section, and in case of conveyance of several stepped products, or double stepped products for example, a trouble such as breakage of the steps tends to occur.